[agauos]

The shoulder washer kit that PMM sells is the exact same kit that's included with the SureFire muzzle devices. I received my SureFire muzzle brake (SFMB-762-5/8-24) today and can confirm it includes the chamfered washer plus an assortment of timing shims. Same as what's for sale in this link:

Surefire Shim Kit, SF3P / SFMB / Warcomp-762, 5/8-24

Check out the deal on Surefire Shim Kit, SF3P / SFMB / Warcomp-762, 5/8-24 at MGW

www.midwestgunworks.com

Is your Scar the original design with the stepped 1:12" barrel and 3-prong flash hider or the redesign with the non-stepped 1:10" barrel and muzzle brake? There is a ton of misinformation and dangerous advice floating around the internet on this so please read the instructions and do as it says. Both PMM and SureFire have decent videos on YouTube but they tend to gloss over the most critical step.

If you have the stepped 1:12" barrel:
On page 3 it says "Note: With SCAR-H, use supplied spacer with chamfer facing away from shoulder." This confuses people because every other rifle calls for the chamfer to be facing the shoulder to act as a relief for the small radius that always exists at the bottom of the threads. If this same orientation is used on the Scar then the washer will have very minimal surface contact or possibly clamp on the chamfered surface (the chamfer OD is very close in size to the barrel OD but I haven't taken measurements). Regardless, the correct method is to flip the washer around like the manual says.

https://www.surefire.com/wp-content/uploads/2020/08/71-01-997_Suppressor-Adapter-Installation_Rev-C.pdf

SureFire should make this more explicit but they clearly haven't updated their manual since FN decided to change the dimensions of the barrel. I've seen a handful of people say they disregarded that advice because they thought it must be a misprint and that, to me, is a very bad idea.

If you have the non-stepped 1:10" barrel:
I'd imagine (but have not confirmed) the washer should be installed the standard way where the chamfer faces the shoulder. The chamfered washer may not even be necessary depending on the thread depth of the flash hider and threaded length of the barrel. You don't want the tip of the barrel threads to bottom out inside the flash hider of you'll be locating the muzzle device off the incorrect surface. I have not seen these in person so don't take my word for it.

Thanks for the info! I do have the 1:10 barrel, looks like I'll just have to see how it works out!

 

[Ex-Racer / Ex-Pat]

Surefire is the gold standard for sure...

 

[LKNGOOD]

I also went with a Surefire SOCOM 762-RC2 Suppressor and a Surefire SOCOM Muzzle Brake for my SCAR 20S.

I also made sure the Shoulder Ring was installed correctly for the SCAR 20S as instructed in the owner's manual.

I also added a few upgraded from MotoTech to help with the recoil including:

• Mototech Buffer Pad Rubberized Nylon
• Mototech Back Plate Torx Screw Set
• Mototech Receiver Rail Torx Screw Set
• Mototech Front Plate Torx Screw Set
• Mototech 3-Select Gas Regulator

 

[PEW Science]

I've been trying to decide what suppressor to get for my 20S for a few weeks and finally made up my mind and have one on order. I was deciding between Dead Air, OSS, and SureFire. Suppressor selection is so subjective and quality test data is hard to come by. Everyone has their own requirements so mine probably differ from yours (and this may be totally irrelevant) but wanted to share in case you hadn't researched all these options.

This recent Pew Science review was the largest deciding factors in going SureFire over Dead Air. I like the quick detach on the Dead Air better than the SureFire. The deciding factor for me was the incredibly low back pressure on the SureFire SOCOM 762-RC2 with no sound penalty over a Dead Air Sandman-L (Figure 13).

Surefire SOCOM762-RC2 .308 Suppressor Test — PEW Science

Surefire SOCOM762-RC2 Silencer Test with back pressure data. Real sound signature data with the Suppression Rating from PEW Science. Hearing Safe determinations for your use case. How does it do as a 308 rifle suppressor? Can it suppress 7.62 NATO? Is it the best 308 hunting suppressor?

pewscience.com

I'm watching the PMM video as I type this but I'd imagine the SCAR can be tuned to run nearly any suppressor. I like the fact that the SureFire should not require any tuning for those times when you're running without a suppressor in addition to a host of other benefits of lower back pressure. The really interesting takeaway I haven't seen mentioned anywhere else is the SureFire performs terribly with the SureFire Warcomp flash hider. Many previous reviewers that were critical of the high SPL numbers on the SureFire suppressor were running the Warcomp so take their numbers with a grain of salt.

Hi guys, I'm Jay, the owner and Technical Director of PEW Science.

I saw this link in my website analytics as I was going through it and had never been to this website before, so I came here to read the discussion, and looks like people have found my test data for the Surefire SOCOM762-RC2. I'm super glad folks are finding it informative and useful.

A couple of things I wanted to highlight -

1. The backpressure metric I computed in that review was (and is) preliminary. The backpressure part of my current research is still undergoing refinement. In the most recent 7.62 Sound Signature Review, which is review 6.36 on the website, I show Revision 2 of the back pressure metric, in which I consider not only the rise time to peak positive phase impulse, but the rate of the rise, as well. So, with regard to the SOCOM762-RC2, it is still predicted to have "low" back pressure, but maybe not as low as I had previously estimated.

2. The sound signatures shown are obviously only valid in the configurations tested, which I'm sure you understand. Changing the host weapon and/or ammunition can change the signature, as you folks know - just wanted to highlight that for people who may see the test report and not know that.

With regard to questions I have for you guys -

A. I am not very familiar with the SCAR weapon system. As I am now an 07/02 I will probably buy one and convert it to full auto because I have been told they are fairly reliable. Seems fun. Have any of you done this?

B. With regard to silencer back pressure sensitivity on this host weapon (5.56 or 7.62 models of the SCAR), what have been your overall observations? Have you folks seen reliable operation with the SOCOM762-RC2 on the 7.62 SCAR? Do my back pressure estimations make sense? What about on the 5.56 version of the SCAR? Furthermore, what about things like the SOCOM556-RC2? Have you tried that on the 5.56 SCAR? I assume folks adjust gas port size with this gun like they do on the Stoner platform, just by a different method. That is fine, but I am interested in particular configurations with particular silencers. Your field data is very valuable.

Thank you for highlighting my research. I appreciate it, and thank you for any thoughts or insight you can provide into the above.

r/

Jay
PEW Science

 

[bbuttons17s]

Hi guys, I'm Jay, the owner and Technical Director of PEW Science.

I saw this link in my website analytics as I was going through it and had never been to this website before, so I came here to read the discussion, and looks like people have found my test data for the Surefire SOCOM762-RC2. I'm super glad folks are finding it informative and useful.

A couple of things I wanted to highlight -

1. The backpressure metric I computed in that review was (and is) preliminary. The backpressure part of my current research is still undergoing refinement. In the most recent 7.62 Sound Signature Review, which is review 6.36 on the website, I show Revision 2 of the back pressure metric, in which I consider not only the rise time to peak positive phase impulse, but the rate of the rise, as well. So, with regard to the SOCOM762-RC2, it is still predicted to have "low" back pressure, but maybe not as low as I had previously estimated.

2. The sound signatures shown are obviously only valid in the configurations tested, which I'm sure you understand. Changing the host weapon and/or ammunition can change the signature, as you folks know - just wanted to highlight that for people who may see the test report and not know that.

With regard to questions I have for you guys -

A. I am not very familiar with the SCAR weapon system. As I am now an 07/02 I will probably buy one and convert it to full auto because I have been told they are fairly reliable. Seems fun. Have any of you done this?

B. With regard to silencer back pressure sensitivity on this host weapon (5.56 or 7.62 models of the SCAR), what have been your overall observations? Have you folks seen reliable operation with the SOCOM762-RC2 on the 7.62 SCAR? Do my back pressure estimations make sense? What about on the 5.56 version of the SCAR? Furthermore, what about things like the SOCOM556-RC2? Have you tried that on the 5.56 SCAR? I assume folks adjust gas port size with this gun like they do on the Stoner platform, just by a different method. That is fine, but I am interested in particular configurations with particular silencers. Your field data is very valuable.

Thank you for highlighting my research. I appreciate it, and thank you for any thoughts or insight you can provide into the above.

r/

Jay
PEW Science

View the video that Jarod at Parker Mountain Machine did. For a civilian he probably has more real word experience with SCARs & suppressors than anyone else. If you can catch him, he's also happy to talk or respond to emails.

 

[PEW Science]

View the video that Jarod at Parker Mountain Machine did. For a civilian he probably has more real word experience with SCARs & suppressors than anyone else. If you can catch him, he's also happy to talk or respond to emails.

Thank you, sir. Yeah I watched that video, and I am fully aware of suppressed operation of semi- and fully-automatic gas operated firearms, but his video does not contain quantitative data or even semi-quantitative data on specific silencer performance on the platform. He does explain the operation, which is nice. I will contact him too. Thank you!

I am looking for user experiences with the aforementioned silencers on this weapon platform. For example, has anyone in this thread fired their 7.62 SCAR with that Surefire silencer, and what exact adjustments did they do to the weapon system, if any. Also, has anyone instead used a silencer with reportedly higher flow restriction (back pressure) on the weapon, and were the adjustments required for weapon function different? Did anyone measure brass patterns, ejection distances, bolt speed, etc?

I realize these questions are somewhat rhetorical, in that the answer is "yes, adjusting the gas on your gun is good." What I'm trying to get at is - is the SOCOM762-RC2 really ok for the SCAR with minimal adjustment, does my data make sense for actual users, etc.

Thanks again

Jay
PEW Science

 

[bbuttons17s]

Thank you, sir. Yeah I watched that video, and I am fully aware of suppressed operation of semi- and fully-automatic gas operated firearms, but his video does not contain quantitative data or even semi-quantitative data on specific silencer performance on the platform. He does explain the operation, which is nice. I will contact him too. Thank you!

I am looking for user experiences with the aforementioned silencers on this weapon platform. For example, has anyone in this thread fired their 7.62 SCAR with that Surefire silencer, and what exact adjustments did they do to the weapon system, if any. Also, has anyone instead used a silencer with reportedly higher flow restriction (back pressure) on the weapon, and were the adjustments required for weapon function different? Did anyone measure brass patterns, ejection distances, bolt speed, etc?

I realize these questions are somewhat rhetorical, in that the answer is "yes, adjusting the gas on your gun is good." What I'm trying to get at is - is the SOCOM762-RC2 really ok for the SCAR with minimal adjustment, does my data make sense for actual users, etc.


Jay
PEW Science

Ask the US Government. Surefire are the suppressors of choice to equip the SCAR H with. Their selection was based on SF's "Total Signature Reduction" that they designed into their suppressors. SF suppressors are know to be one of the lowest backpressure cans manufactured. Personally I use the SF SOCOM RC-2 7.62 on my SCAR 17S with both the 13" & 20" barrels and the only modification that I made was to install a 1.35mm gas jet instead of the factory1.45mm which came with 16" barrel. On my particular rifle, the 1.35mm gas jet was the lowest size that the rifle would run reliably with, always shooting military surplus ammunition. My firearm shot just fine using the SF SOCOM RC-2 7.62 suppressor with either size gas jet but I wanted to "tune" it to minimize recoil by installing the smaller gas jet. Also, every firearm shoots a little differently, so what's the best setup for one may not be the best for another. That's a variable that you will never be able to quantify.

That being said, I think you're getting way into the weeds trying to verify the already known facts and performance of the SF SOCOM suppressors. They're universally considered to be one of the best performing suppressors, if not the best, and that's why they're chosen by more militaries in the world than any other. I know of no one that takes their SCAR to the range to "measure brass patterns, ejection distances, bolt speed, etc.?". Such analysis is best left for the laboratory and then, to what end would that assembled information be of any use to anyone? Surefire has already done it.


The Surefire website has some excellent videos explaining the design, manufacturing and use of their products in real world military applications, not just by the casual weekend warrior.

 

[thehun]

Thank you, sir. Yeah I watched that video, and I am fully aware of suppressed operation of semi- and fully-automatic gas operated firearms, but his video does not contain quantitative data or even semi-quantitative data on specific silencer performance on the platform. He does explain the operation, which is nice. I will contact him too. Thank you!

I am looking for user experiences with the aforementioned silencers on this weapon platform. For example, has anyone in this thread fired their 7.62 SCAR with that Surefire silencer, and what exact adjustments did they do to the weapon system, if any. Also, has anyone instead used a silencer with reportedly higher flow restriction (back pressure) on the weapon, and were the adjustments required for weapon function different? Did anyone measure brass patterns, ejection distances, bolt speed, etc?

I realize these questions are somewhat rhetorical, in that the answer is "yes, adjusting the gas on your gun is good." What I'm trying to get at is - is the SOCOM762-RC2 really ok for the SCAR with minimal adjustment, does my data make sense for actual users, etc.

Thanks again

Jay
PEW Science

Seriously? This subject has been beaten to death over the years...

Google is your friend ... closest you'll get to an "approved" SCAR suppressor is the SOCOM762-RC2 ... sometimes there is the legacy SCAR-H suppressor released by Surefire...but that hasn't happened in years...

There are people that have reported busted bolt carriers because they ran the SCAR in OEM configuration without any tuning with traditional baffle suppressors...

While the Surefire, Dead Air and Rugger considered "low-pressure" they aren't to the sense of OSS and still require tuning...

Many of us use different suppressors...ALL suppressors regardless of make will require your OWN tuning ... for example ... just because my YHM R2 works great with a 1.3mm at 1100ft elevation for me...does not mean it will work the same in Denver CO...or you might be running hot reloads...that will require a complete different set of experimentation...I only use M80 or M118LR so my experience on tuning will differ than most SCAR users that might use hotter, commercial .308 ammo...

So, you have to decide what suppressor you want...and tune it...SCARs work great with suppressors once tuned...but out of the box, unless you have an OSS suppressor...they won't be "plug-n-play"...

ANY traditional baffle suppressor regardless if its Dead Air, Rugged, Surefire or YHM...will need your own specific tuning...

As LKNGOOD mentioned...I've done the same, minus the 3-pos regulator and I went with a 1.3mm jet instead with my YHM R2:

• Mototech Buffer Pad Rubberized Nylon
• Mototech Back Plate Torx Screw Set
• Mototech Receiver Rail Torx Screw Set
• Mototech Front Plate Torx Screw Set
• Mototech 3-Select Gas Regulator or tuned gas jet

YOU WILL NOT HAVE ISSUES WITH THE SUREFIRE RC2 or matter of fact any other suppressors as long as you take care of what needs to be taken care of in the gas system, receiver screws and buffer pad that has been said on the interwebz for many many years now...

 

[codemonkey]

I just got my 20S as well and deciding on a suppressor. My requirement is probably what everyone else's requirement is: shoot suppressed and unsuppressed reliably without any irreversible modification on the gun (no barrel chopping plz) and no major adjustment when switching between the 2. Super glad I came across this thread.

First off, from what I've read suppressors cause issues for the 20S mainly because of the back pressure. I could never find 100% uninterrupted 40 min to concentrate and watch the whole PMM video with full concentration but I think that's the gist of it. (apologize if I am wrong I will find time to actually watch the video with full attention). With that, I started to research which can has:

• The lowest back pressure
• Passable suppression performance
• Reputable brand

Although I have ZERO military background but I am an engineer who is comfortable with data and papers. Came across Pew Science's analysis on OSS HX-QD 762 and it is obvious that the OSS has much smaller back pressure comparing to the Surefire SOCOM RC2 (0.05 vs. 0.12 as shown in the back pressure section). This is something we should base our purchasing decisions off of. Not the "trust me bro I know a guy" posts on the internet. Unfortunately I ordered a SOCOM RC2 because of the following post:

finally done with my scar

just got my stamp and can. SCAR 17 specs Voltor Stock Grip Pod SAW Geissele Super SCAR Trigger Nikon M-Tactical .308 4-16X42SF Matte BDC800 W/ Mount and Sunshade May change later, but the scope can out shoot my skills. 3-2-1 sling, don't remember who i bought it from OSS HX-QD 762 OSS 762...

www.fnforum.net

I am thinking about ordering an OSS. I'm sure I can use the RC2 on other guns such as my SR-25 since it is a phenomenal gun.

Re:

Google is your friend ... closest you'll get to an "approved" SCAR suppressor is the SOCOM762-RC2 ... sometimes there is the legacy SCAR-H suppressor released by Surefire...but that hasn't happened in years...

This is false for the Mk20 SSR / 20S. The only designated suppressor that is announced publicly officially is the FA762SV. NOT the SOCOM RC2. Big difference here. The FA762SV utilizes an over-the-barrel design. They don't even function the same way. Yeah sure it has the SOCOM name they look similar but they are NOT the same.

 

[670]

I have the 1:10 barrel and put a deadair nomad-ti and have been pretty happy.

 

[maynardjay]

Have any of you tried the new KNS system? I have one on an AK, and it's a fantastic solution. If it performs similarly it may be a good solution. I have found the OSS to be very loud with .30 projectiles, and I would love to be able to run a can with significantly more flow restriction.

 

[SCAR911]

What suppressor should I get might as well be, what suppressor do you own? Also, Ford or Chevy trucks? And 9mm vs 45?

 

[Kev]

Chevy and 9mm. No contest